Vincent and Tara are making triangles with the class construction set. They have a pile of strips of different lengths. How many different triangles can they make?

Whose Sandwich?

Stage: 1 Challenge Level:

Why do this
problem?

This problem requires logical thinking and would be a good
context in which to discuss different ways of representing
mathematics.

Key questions

What could you write down or draw to help?

What kind of sandwich did Jane order?

Possible support

It would help to talk to learners about what they could write
or draw as they work on this problem. You could start
just by listing all four children's name across the top of a piece
of paper, for example, which might help some pupils get started.

The NRICH Project aims to enrich the mathematical experiences of all learners. To support this aim, members of the
NRICH team work in a wide range of capacities, including providing professional development for teachers wishing to
embed rich mathematical tasks into everyday classroom practice. More information on many of our other activities
can be found here.